KR101854128B1 - Composition for Lime Mortar Comprising Natural Hydraulic Lime, Blast Furnace Slag and Limestone Powder - Google Patents

Abstract

The present invention relates to a composition for a three component lime mortar comprising natural hydraulic lime (NHL) powder, blast furnace slag (BFS) powder, and limestone fine powder (LP). The three-component lime mortar composition of the present invention has remarkably improved physical properties of compressive strength and cohesion property by the addition of blast furnace slag and limestone fine powder, and since the natural hydraulic lime is included as the main raw material, Environment-friendly properties such as moisture resistance, antifungal activity. The composition for lime mortar of the present invention can be used as eco-friendly interior and exterior materials, finishing materials, bonding materials and the like of buildings.

Description

Technical Field [0001] The present invention relates to a composition for lime mortar containing natural hydraulic lime, blast furnace slag, and limestone fine powder.

The present invention relates to a composition for lime mortar containing natural hydraulic lime, blast furnace slag, and limestone fine powder as an effective ingredient.

Natural hydraulic lime (NHL) is a multifunctional construction material corresponding to the uppermost layer of hydraulic lime. It has better dimensional stability and reworkability than non-hydrated lime and has a significantly lower whitening effect. In addition, the inside of the cured body is formed as a porous material and exhibits environmentally excellent characteristics such as constant temperature, humidity, anti-moldiness, adsorbability of harmful substances and the like. Although it is possible to manufacture functional materials such as lightweight bricks, porous concrete and porous mortar by processing existing building materials, it is known that most of them are not environmentally friendly and have poorer insulation performance than lime binders (Kalagri et al., 2010; Harrison et al., 2005). Due to these excellent properties, many countries are already attracting attention as eco-friendly construction materials and are being used for various purposes in new and old buildings. However, some researchers and builders can use it as a multifunctional material, but some improvements are needed. NHL is a long-term curing, performance-enhancing material that is somewhat difficult to improve strength and coagulation properties at early ages without the addition of other materials (Kalagri et al., 2010, Lawrence, 2006). In general, it is common to add inorganic admixtures such as slag, silica fume, and fly ash as a primary method to improve physical properties, but it is difficult to meet the settling time required in a practical operation (Alberto, 2010 ).

Recently, limestone powder (LP) is an alternative material for high strength and high flowability, and consumption rate as binder is increasing. Because it is directly used without the step of processing through combustion, it is possible to reduce the amount of generated CO2, (Jung et al., 2006; Lothenbach et al., 2008). When a large amount of LP is contained in the hardened body, it increases the bonding force between the clinker and the aggregate, and improves the intergranular compactness because the particles act as a filler (Alberto, 2010, Lothenbach et al., 2008 , Heikal et al., 2000). In addition, it is possible to promote the nucleation of CSH gel to improve the physical properties by hydrate formation in the initial hydration and to retard the conversion of ettringite into monosulfate, (Lothenbach et al., 2008, Heikal et al., 2000). However, the effect of the limestone fine powder is aimed at improving the performance of the mortar and concrete products by using Ordinary Potland Cement (OPC) instead of improving the hydraulic lime performance. Korean Patent Laid-Open No. 10-2006-0006399 discloses a method of adding calcium oxide and natural calcium carbonate as main ingredients to slaked lime made of ordinary high-quality limestone instead of hydraulic lime based on low-grade limestone as a raw material, Cement (OPC) has been added, but the results of measuring the effect of adding limestone powder to natural hydraulic lime on the coagulation characteristics and compressive strength are not presented. So far, little research has been done to improve the strength and coagulation characteristics of natural hydraulic lime using limestone powder at home and abroad.

The patent documents and references cited herein are hereby incorporated by reference to the same extent as if each reference was individually and clearly identified by reference.

Korean Patent Publication No. 10-2013-0113190 Korean Patent Publication No. 10-2006-0006399

Kalagri, A., Miltiadou-Fezans, A. and Vintzileou, E., 2010, Materials and Structures, Vol. 66, No. 43, pp. 1135-1146. Harrison, A. John W. and FCPA, B.Sc. B.Ec., 2005, TecEco Pty. Ltd., Hobart, Tasmania, Australia. Lawrence, R. M. H., 2006, "A study of carbonation in non-hydraulic lime mortars," University of Bath. Alberto, S. A., and Francisco, H. O., 2010, Cement and Concrete Research, Vol. 40, pp. 66-76. Lee, J. K., Chu, Y. S. and Song, H., 2011, Journal of the Korean Ceramic Society, Vol. 48, No. 6, pp. 584-588. J., S., Lee, S., T., Kim, J., Park, K., P. and Kim, S., 2006, J. of Korean Institute of Resources Recycling, Vol. 15, No. 3, pp. 74-80. Lothenbach, B., Saout, G. L., Gallucci, E. and Scrivener, K., 2008, Cement and Concrete Research, Vol. 38, pp. 848-860. Heikal, M., El-Didamony, H. and Morcy, M.S., 2000, Cement Concrete Research, Vol. 30, pp. 1827-1834. Choi, W. H., Park, C. W., Jung, W. K. and Kim, K. H., 2012, International journal of highway engineering, Vol. 14, No. 4, pp. 37-49.

The present inventors have made efforts to produce a lime mortar having excellent physical properties such as compressive strength and coagulation characteristics and excellent environment-friendly characteristics such as adsorption of harmful substances. As a result, mortar was prepared by adding blast furnace slag powder and limestone powder to natural hydraulic lime powder having environment-friendly characteristics, and it was experimentally confirmed that the mortar thus produced was excellent in compressive strength and coagulation property, thereby completing the present invention Respectively.

Accordingly, an object of the present invention is to provide a composition for lime mortar containing natural hydraulic lime powder, blast furnace slag powder, and limestone fine powder excellent in environmental characteristics and physical properties.

Other objects and technical features of the present invention will be described in more detail with reference to the following detailed description, claims and drawings.

According to one aspect of the present invention, there is provided a composition for lime mortar comprising natural hydraulic lime powder, blast furnace slag powder, and limestone fine powder.

As used herein, the term " natural hydraulic lime " (NHL) refers to naturally hydrated lime. Preferably, the natural hydraulic lime used in the composition for lime mortar of the present invention is domestic natural hydraulic lime.

According to one embodiment of the present invention, the natural hydraulic lime is produced by calcining low-grade waste limestone at 1000-1500 ° C for 1-5 hours and then dry-hydrated.

According to one embodiment of the present invention, the natural hydraulic lime of the present invention comprises Ca (OH) 2, C2S, C3S, unreacted SiO2, and gehlenite as mineral phases.

According to another embodiment of the present invention, the average diameter of the natural hydraulic lime powder of the present invention is 8-12 占 퐉, more preferably 9-11 占 퐉, and most preferably 10 占 퐉.

According to another embodiment of the present invention, the natural hydraulic lime powder of the present invention is contained in an amount of 50 to 70% by weight based on the total composition of the present invention.

As used herein, the term "blast furnace slag (BFS)" means that the blast furnace slag is quenched with water and solidified in the form of sandy vitreous slag.

According to one embodiment of the present invention, the blast furnace slag of the present invention comprises SiO2 and an asteroid as an amorphous mineral phase.

According to another embodiment of the present invention, the blast furnace slag of the present invention comprises 40-45% of CaO, 25-30% of SiO2, and 12-18% of Al2O3.

According to another embodiment of the present invention, the average particle diameter of the powder of the blast furnace slag of the present invention is 10-14 占 퐉, more preferably 11-13 占 퐉, and most preferably 12 占 퐉.

According to another embodiment of the present invention, the blast furnace slag powder in the present invention is contained in the range of 5-20% by weight based on the total composition of the present invention.

As used herein, the term " Limestone Powder (LP) " refers to limestone, which is a type of industrial by-product that occurs during the cement manufacturing process and has a very high degree of powder.

According to one embodiment of the present invention, the limestone fine powder of the present invention comprises CaCO3 as a mineral phase, and further comprises a trace amount of SiO2 and dolomite.

According to another embodiment of the present invention, the average particle size of the limestone fine powder of the present invention is 12-16 mu m, more preferably 13-15 mu m, and most preferably 14 mu m.

According to another embodiment of the present invention, the limestone fine powder of the present invention is contained in an amount of 10-30% by weight based on the total composition of the present invention.

According to a most preferred embodiment of the present invention, the composition for lime mortar of the present invention comprises 60% by weight of natural hydraulic lime powder, 20% by weight of blast furnace slag powder, and 20% by weight of limestone fine powder.

The present invention relates to a composition for a three component lime mortar comprising natural hydraulic lime (NHL) powder, blast furnace slag (BFS) powder, and limestone fine powder (LP). The three-component lime mortar composition of the present invention has remarkably improved physical properties of compressive strength and cohesion property by the addition of blast furnace slag and limestone fine powder, and since the natural hydraulic lime is included as the main raw material, Environment-friendly properties such as moisture resistance, antifungal activity. The composition for lime mortar of the present invention can be used as eco-friendly interior and exterior materials, finishing materials, bonding materials and the like of buildings.

Figure 1 shows the XRD results of the raw materials used in this study. Panel (a) is the domestic NHL produced using low-grade limestone in Korea, panel (b) is the BFS for concrete mix produced in Korea, and panel (c) is XRD analysis of LP (high-grade limestone) Results.
FIG. 2 shows the results of particle size analysis of domestic NHL, BFS and LP.
FIG. 3 shows the results of XRD analysis according to the BFS mixing amount of the domestic NHL-BFS-LP three component paste.
FIG. 4 shows the results of XRD analysis according to the LP mixing amount of the domestic NHL-BFS-LP three component paste.
FIG. 5 shows DSC analysis results of the domestic NHL-BFS-LP three component paste.
FIG. 6 shows SEM analysis results of NHL pastes mixed with 10% BFS and 20% LP.
7 shows the SEM analysis results of the paste according to the LP mixing amount at a BFS of 10% at 28 days of age.
FIG. 8 shows the results of analyzing the pore size and distribution of the domestic NHL-BFS-LP three-component paste.
9 shows the results of compressive strength measurement according to BFS and LP contents.

Example

1. Experimental material

Fig. 1 shows the XRD analysis results of the raw materials used in this embodiment. The panel (a) of FIG. 1 is a domestic natural hydraulic lime (NHL) manufactured using domestic low-grade limestone and the panel (b) of FIG. 1 is a blast furnace slag and BFS) and the panel (c) of FIG. 1 is a result of XRD analysis of limestone powder (Limestone Powder, LP, high-grade limestone) produced in Danyang area, Chungbuk province using a ball mill. The panel (a) of FIG. 1 shows the XRD analysis results of the domestic NHL. Domestic NHL was prepared by dry hydration of low - grade waste limestone calcined at 1250 ℃ for 2 hours. The main minerals were Ca (OH) ₂ , C ₂ S, C ₃ S, unreacted SiO ₂ , and gehlenite. Hydraulic minerals C ₂ S and C ₃ S were produced smoothly, The presence of Ca (OH) ₂ suggests that hydration reaction of NHL itself in Korea and hydration of BFS by hydrothermal reaction are effective.

The panel (b) of FIG. 1 shows the XRD analysis results of the BFS. From the XRD analysis, it was found that SiO ₂ and anisotrope were contained as amorphous mineral phases. According to the results shown in the panel (c) of FIG. 1, in the case of the LP for the binder, the major mineral phase is CaCO ₃ and contains a small amount of SiO ₂ and dolomite.

Table 1 below shows the chemical analysis results of BFS and LP. Chemical analysis BFS is _{CaO 42.44%, SiO 2 27.40%} , Al 2 O 3 as a 14.79% was confirmed to contain a large amount of SiO ₂ and Al ₂ O _3, LP has a CaO content of impurities less than 54% It was confirmed that it is a high quality limestone with very low content.

Chemical composition BFS LP Na ₂ O 0.26 - MgO 8.59 0.95 Al ₂ O ₃ 14.79 0.10 SiO ₂ 27.41 0.21 P ₂ O ₅ 0.10 - SO ₃ 3.90 - K ₂ O 0.82 - CaO 42.45 54.94 TiO ₂ 0.60 - MnO 0.18 - Fe ₂ O ₃ 0.57 0.12

FIG. 2 shows the results of particle size analysis of domestic NHL, BFS and LP. As a result of the particle size analysis, the average particle size of domestic NHL was about 10 μm and the particle size distribution was formed in hyperbolic shape. This is probably due to the fact that Ca (OH) ₂ is composed of fine particles and C ₂ S and C ₃ S are hydrated minerals. In the case of BFS, the average particle size was about 12 μm and the particle size was relatively large. In case of LP, the average particle size was 14 μm, which is the largest particle size distribution.

2. Experimental Method

NHL-BFS-LP three component paste and mortar were prepared according to the mixing ratio. In order to confirm the change of the contents according to the LP content, the contents were varied to 10%, 20% and 30%. In order to confirm the degree of hydration promotion based on the results that LP promotes the hydration reaction, To 5%, 10% and 20%, respectively.

2-1. Paste experiment

NHL occurs primarily in the hydration reaction of hydroponic mineral phases, and secondary characterization by the carbonation reaction proceeds simultaneously from the formation of capillary pores and moisture loss inside the cured body. Therefore, in order to confirm mineralization changes by hydration reaction and carbonation reaction even at short ages in consideration of laboratory scale in paste experiment, samples were made with a thin thickness of 5 - 8 mm. The sample corresponding to each aged day was stopped hydration using acetone. After preprocessing suitable for each instrument analysis, X-ray diffraction test (XRD: D / max 2500V / P, Rigaku Co. Ltd. Japan) Scanning calorimetry and thermogravimetric analysis (TG / DSC: STA 449C Jupiter, NETZSCH Co, Ltd. Germany), scanning electron microscope observation (SEM: S-4300, HITACHI Co. Ltd. Japan) 9520, Micromeritics Co. Ltd. USA). Table 2 and Table 3 show sample names of the NHL paste corresponding to the production conditions of the three-component NHL paste and the compounding ratios, respectively.

Sample Water mixture ratio Condition Domestic NHL 0.6 Mixture with BFS and LP Addition of BFS (%): 5, 10, 20 LP addition (%): 10, 20, 30 Curing conditions: 20 < 0 > C under a relative humidity of 95% Hydration time (day): 1, 3, 7, 28

NHL addition (%) BFS addition (%) LP addition (%) Sample name 100 0 0 NHL 90 10 0 NHL + S10 80 20 0 NHL + S20 85 5 10 NHL + S5 + C10 75 5 20 NHL + S5 + C20 65 5 30 NHL + S5 + C30 80 10 10 NHL + S10 + C10 70 10 20 NHL + S10 + C20 60 10 30 NHL + S10 + C30 70 20 10 NHL + S20 + C10 60 20 20 NHL + S20 + C20 50 20 30 NHL + S20 + C30

2-2. Mortar experiment

The mortar water content was measured as flow (165 ± 3) mm, taking into account the difference in workability depending on the composition ratio of the admixture in the mortar, in accordance with BS EN 459-1: 2010 . Each sample was prepared by mortar after primary pre-mixing with NHL (+ BFS, + LP): sand: water = 1: 3: x (flow (165 ± 3) mm) (40 x 40 x 160) mm. The mortar was cured at a temperature of 20 ° C and a relative humidity of 95%. The compressive strength of the mortar was measured at 7 days and 28 days. The compressive strength was 144 kN / min. The mortar production conditions are shown in Table 4, and the sample names are the same as the paste production conditions in Table 3. [

Sample Water mixing ratio Condition Domestic NHL Flow (165 ± 3) mm Mixture with BFS and LP BFS addition (%): 0, 5, 10, 20 LP addition (%): 0, 10, 20, 30 Curing conditions: 20 < 0 > C under a relative humidity of 95% Curing time (day): 7, 28

The sample preparation and test method for the condensation test was in accordance with BS EN 459-1: 2010, and the sample under measurement was stored in a thermo-hygrostat at a temperature of 20 ° C and a humidity of 95%. The measurement of cleanliness on the top surface of the mold was carried out using a non - contact measuring device. Stability and air volume were measured according to BS EN 459-1: 2010.

Experiment result

FIG. 3 shows the results of XRD analysis according to the BFS mixing amount of the domestic NHL-BFS-LP three component paste. When LP mixing amount is same as 20%, XRD analysis according to BFS mixing amount did not confirm the difference of major mineral phases according to BFS mixing amount. However, in the panel (c) of FIG. 3 in which the gypsum inherent in the BFS remained and the BFS content was relatively large at 20%, ettringite was formed from the beginning of hydration. It is known that when LP is contained in a large amount, nucleation of hydrate is accelerated and excellent properties for improvement of initial durability of hardened product are obtained (Heikal et al., 2000). Therefore, in the experiment of the present invention, it was expected that the difference in the amount of hydrate formation due to the difference in the amount of BFS could be confirmed. However, in the XRD analysis, only a small amount of BFS was contained in the sample containing a large amount of BFS ettringite was formed. The formation of calcium silicate and calcium aluminate hydrate was not observed during the hydration time up to 28 days of age. The rate of change of Ca (OH) ₂ peak around 18 ° was insignificant compared with that of 28 days to 1 day. It was found that carbonation for CaCO ₃ production gradually progressed with hydration of BFS. Whether this tendency is suppressed by the own characteristics of the LP crystal grains existing in the cured product or the composition ratio of LP is higher than that of the whole mineral phase, Judgment should be confirmed through additional instrumental analysis.

FIG. 4 shows the results of XRD analysis according to the LP mixing amount of the domestic NHL-BFS-LP three component paste. As a result of XRD analysis according to LP mixing amount at BFS mixing amount 10%, the major mineral phases were Ca (OH) ₂ , CaCO ₃ , C ₂ S, C ₃ S, CaSO ₄ .2H ₂ O and ghelenite, , But the composition ratio of the other minerals was decreased as the amount of LP was increased. If the constituent ratio of hydraulic minerals in the total constituent minerals in the sample is decreased, it will be difficult to improve the durability by hydraulic minerals even if the hydration reaction continues. However, since the LP crystal grains act as a filler of the pores formed in the cured product, the durability of the LP filler can be expected to be improved because the self-filling ratio is increased. It is possible to improve the complementary properties to some extent because it increases the bonding force.

FIG. 5 shows DSC analysis results of the domestic NHL-BFS-LP three component paste. The panel (a) of FIG. 5 shows the result of DSC analysis according to the ages of pastes containing 10% of BFS and 20% of LP and the panel (b) of FIG. 5 shows DSC analysis And panel (c) of FIG. 5 shows the result of DSC analysis according to the LP content based on BFS 10%. As a result of the analysis of the panel (a) of FIG. 5, the peaks near 100 ° C and 170 ° C are the endothermic peaks attributable to calcium silicate hydrate, ettringite and C ₄ AH ₁₃ , It was found that the peak around 107 ° C was greatly decreased as the ettringite was converted into monosulfate with the increase of the temperature and the peak around 170 ° C was slightly increased due to the continuous reaction of BFS . The peak around 800 ℃ could be confirmed that the peak increased after 28 days of age, which means that the carbonation reaction is proceeding. As hydration reaction and carbonation reaction of hydraulic minerals progressed, the Ca (OH) ₂ peak near 500 ℃ gradually decreased. As a result of the DSC analysis according to the BFS mixing amount in the panel (b) of FIG. 5, it was confirmed that the hydration reaction was promoted as the mixing amount of BFS was increased, and the peak due to C ₄ AH ₁₃ hydrate around 170 ° C was increased insufficiently. As a result of DSC analysis with respect to the LP content in the panel (c) of Fig. 5, the peak size due to the hydrate around 100 캜 or around 170 캜 hardly changed. It can be seen that the difference in the amount of hydrate generated by fixing the BFS to 10% at 28 days is not large, and LP is present as a filler and a binder.

FIG. 6 shows SEM analysis results of NHL pastes mixed with 10% BFS and 20% LP. In the first day of the panel (a) of Fig. 6, an acupuncture ettringite at the initial stage of hydration starts to be generated. From the 3rd day of the panel (b) of Fig. 6, Shaped CSH gel was produced. On the 7th and 28th days of the panel (c) and panel (d) of FIG. 6, it was confirmed that the hydration of the ettringite and the CSH gel continuously proceeded to form agglomerates in the form of large agglomerates there was. LP crystal grains were found to be attached to the surface of mineral particles from the early ages. As the age became longer and the hydration reaction progressed, they were distributed on the surfaces and inside of the hydrates and the entangled hydrates. LP particles do not exhibit their own hydration reactivity, such as pozzolanic reaction, but the crystallinity of the surface of the LP itself grains become disarranged, increasing the bonding force with hydrates (Choi et al., 2012). It is believed that this results in an improvement in physical properties such as strength and coagulation.

7 shows the SEM analysis results of the paste according to the LP mixing amount at the BFS 10% at 28 days of age. As the amount of LP was increased, the amount of hydrate was increased and the mass of hydrate was also formed. Also, it seems that the ettringite of the needle-like type remained until the 28th day of hydration, because the reaction with the gypsum mixed in the BFS continued.

FIG. 8 shows the results of analyzing the pore size and distribution of the domestic NHL-BFS-LP three-component paste. Panel (a) of FIG. 8 shows the results of analysis of pore distribution according to the ages of pastes containing 10% of BFS and 20% of LP, and panel (b) (C) of FIG. 8 is a pore distribution analysis result according to the LP content based on BFS 10%. In the case of the panel (a) of FIG. 8, as the age increases, the pore size becomes smaller and the pore distribution becomes narrower. As the age increases, calcium silicate and calcium aluminate-based hydrates continue to be produced. Therefore, the size of the pores decreases due to the micro-pore densification inside the cured body, . The pore size and distribution results according to the BFS content in the panel (b) of FIG. 8 also indicate that the BFS content is directly related to the formation rate and production amount of the hydrate, and as the BFS mixing amount increases, It was confirmed that the pore size was decreased. In the S 20 + C 20 sample, the density of the cured body was increased and the distribution ratio of the micropores was the smallest. Hydration when higher the densification of the durability due to the initial hydrate quickly, but can simply be expressed as physical properties are excellent due to the monohydrate, is the fine pore closure in the long run too quickly carbonation reaction because it does not facilitate the movement of CO ₂ It is expected that the proper formulation ratio will be required because the secondary physical property can not be expressed sufficiently. As a result of analyzing the pore size and the pore distribution according to the mixing amount of LP in the panel (c) of FIG. 8, it was found that the pore size decreased as the LP mixing amount increased. Although LP particles act as a catalyst promoting the formation of hydrates, DSC analysis of the panel (c) of FIG. 5 shows that there is no significant difference in the amount of hydrates generated depending on the LP content, and the contribution of the LP itself as a filler . Therefore, as the LP mixing amount increases, the compactness of the internal pores due to the filler increases and the pore size becomes smaller.

Table 5 shows the results of mortar physical tests according to the formulation composition shown in Table 4 above. As a result of compressive strength test, the strength was lowered to 1.3 MPa on 28th day when inorganic additives were not used. The compressive strength of blast furnace slag was increased up to 4.0 MPa, but it was more than 10 hours in condensation. The results of mixing blast furnace slag and limestone powder showed that the compressive strength increased as the age increased and the BFS content increased. These results suggest that as the DSC and SEM analysis results show, the effect of the hydrate production on the BFS content and the LP particle itself are complementary and the internal density is increased. In the case of LP, the compressive strength is generally increased as the content is increased. However, when the content is more than 30%, the compressive strength is decreased. When the LP is contained in an excessive amount, the content of hydrates in the proportion of the total mineral phases in the cured product is relatively decreased, which adversely affects the strength enhancement (Choi et al., 2012) As described above, since the size of the pores is small and the distribution is low, it is difficult to expect immediate physical properties by the carbonation reaction. Therefore, when the LP content is 30%, the decrease in the compressive strength means that the LP content in the hardened product is excessively contained, which is out of the complementary phase. It is important to select an appropriate blending ratio in order to exhibit the optimum physical performance . Compared with products conforming to the EU standard according to the compressive strength measurement values, the three samples in panel (c) of FIG. 9 correspond to NHL 5 and the panels (a) and (b) NHL 2 to NHL 3.5. ≪ tb > < TABLE > In addition, the optimal mixing ratio was found to be 60% of NHL + 20% of BFS + 20% of LP with a compressive strength of 5.7 MPa at 28 days of age.

As a result of the measurement of the coagulation, it was found that when the mineral admixture was not added, it was impossible to measure the termination of the quick drying for more than 40 hours. When the blast furnace slag was added in an amount of 10% by weight or 20% by weight, it was possible to obtain a somewhat effect of condensation pulling. In order to overcome this, limestone powder was added. S 20 + C 10, S 20 + C 20, and S 20 + C 30 corresponded to NHL 5, which had the best physical properties among types of NHL, And S 10 + C 10, S 10 + C 20, and S 10 + C 30, which correspond to the characteristics of NHL 5 in about 6 hours, but finally reaching NHL 3.5 in 19-23 hours Respectively.

S 5 + C 10, S 5 + C 20, and S 5 + C 30 were also observed in NHL 5 for about 8 hours, but the ending time was 31 hours, which was consistent with NHL 3.5. As shown in FIG. 8, the difference in the condensation characteristics depending on the mixing amount of each admixture is closely related to the influence of the LP particles adhering to the surfaces of the respective minerals, the hydration promotion phenomenon by LP, the amount of hydrates and the kinds of hydrates . It seems that the condensation time is shortened by this complex interrelationship, and it is thought that this characteristic can be applied both in practical application and usefulness at practical application. As a result of the measurement of stability and air content, the stability was 0 to -1.0 mm and the air content was 1.6% to 3.9% even when the limestone fine powder was added, including the case where no inorganic admixture was added. . The addition of blast furnace slag and limestone powder to improve the compressive strength and coagulation property of NHL alone could overcome the disadvantages of NHL without affecting other physical properties. In general, various additive materials may be used to overcome the disadvantages, but it may show poor results in stability and air quantity. In order to overcome this phenomenon, blending of blast furnace slag and limestone fine powder is a proper combination for obtaining complementary effect can do.

Three-component system
Natural hydraulic lime
Composition Stability Mortar test Condensation characteristics Compressive strength Air volume Opening time Closing time mm MPa % Time (minutes) 7 days 28th NHL 0 0.7 1.3 1.5 Over 40 h - NHL + S10 0 1.2 2.2 3.2 24 h 30 min 35 min NHL + S20 0 2.8 4.0 3.5 10 h 30 min 19 h 30 min NHL + S5 + C10 0 1.0 1.4 3.0 8 h 30 min 31 h NHL + S5 + C20 0 1.0 1.4 1.36 8 h 30 min 31 h NHL + S5 + C30 0 0.7 1.1 1.9 8 h 31 h NHL + S10 + C10 -0.2 1.6 2.6 1.6 6 h 23 h NHL + S10 + C20 0 1.7 3.3 2.2 6 h 19 h NHL + S10 + C30 -0.2 1.6 2.8 3.9 5 h 30 min 19 h NHL + S20 + C10 -0.5 3.1 3.9 2.8 5 h 10 min 10 h 30 min NHL + S20 + C20 -0.5 3.1 5.7 2.3 5 h 11 h NHL + S20 + C30 -1.0 3.0 4.5 2.3 5 h 11 h

conclusion

(I) Ettringite and calcium silicate hydrate were formed at the initial stage of hydration according to the addition of LP, and it was found that the LP crystal particles affected the hydration rate of the hydrate. It is also found that the LP particles adhering to the surface of the minerals are formed into a mass of hydrates and contribute to the bonding force with the respective hydrates or mineral phases.

(Ⅱ) Compressive strength test showed that compressive strength increased with increasing amount of BFS, and when BFS 20% and LP 20% were mixed, compressive strength was 3.1 MPa at 7 days and 5.7 MPa at 28 days And showed excellent characteristics. However, the compressive strength tends to decrease when the LP mixing amount exceeds 30% in most samples.

(Iii) As a result of the measurement of condensation, all samples had relatively good characteristics within 10 hours, and the finalization time was at least 10 hours and 30 minutes to 31 hours. S 20 + C 10, S 20 + C 20, and S 20 + C 30 correspond to NHL 5, which exhibits the best physical properties of NHL, when classified according to the EU standard. The six samples conformed to NHL 3.5.

(Iv) As the content of BFS and LP content increased, the physical properties such as compressive strength and coagulation property were improved. When the proper mixing ratio was set according to the use environment and application place, the inner and outer materials, finishing materials and bonding materials It is expected that the range of application as a versatile eco-friendly lime binder can be expanded.

The specific embodiments described herein are representative of preferred embodiments or examples of the present invention, and thus the scope of the present invention is not limited thereto. It will be apparent to those skilled in the art that modifications and other uses of the invention do not depart from the scope of the invention described in the claims.

Claims (6)

60 weight% of a natural hydraulic lime powder having an average particle diameter of 8-12 占 퐉, 20 weight% of a blast furnace slag powder having an average particle diameter of 10-14 占 퐉 and 20 weight% of a limestone fine powder having an average particle diameter of 12-16 占 퐉 As a composition for a mortar, when water is added to the total volume of the above composition in a volume ratio of 0.6, it is hydrated to have a condensation termination time of 11 hours and satisfy the EU standard NHL5 (compression strength 5 MPa to 15 MPa) By weight based on the total weight of the mortar composition.
delete delete delete delete delete

Images